Sigma has launched the APS-H version of its SD Quattro camera, ahead of the reports saying it would come on December 20th. The SD Quattro H is a 51 megapixel mirrorless camera sporting an APS-H Foveon X3 Quattro CMOS sensor. Like the “regular” SD Quattro, it also features the latest in Sigma’s Dual TRUE III image processor and takes full advantage of Sigma’s lens lineup including the Art, Contemporary, and Sport global vision lenses made for high megapixel cameras.

For those unfamiliar with the SD Quattro H, it features similar design elements of its lower megapixel brother, the SD Quattro. Both utilize a magnesium alloy body that is dust and splash proof by design. The two cameras also feature dual mode autofocus that combines phase detection and contrast detection for improving both focus speed and accuracy. Focus settings also include modes such as movement prediction, face detection, and focus peaking. The viewfinder in each camera is a 2.3 megapixel display that covers close to 100% of the field-of-view. An all-new “Super-Fine Detail” mode should appeal to photographers looking to get the most potential from the Quattro sensor. This mode captures seven different exposures and merges them into one shot for an image with extensive dynamic range. Each of the seven images can also be extracted individually as well.

While the sensor structure of the SD Quattro H is similar to its sibling, it differs in that it uses a 25.5 megapixel top layer on the sensor just for capturing detail (the SD Quattro’s top layer is 19.6 megapixels). The underlying layers of the sensor are used to capture Red and Green color information all without the use of a low pass filter. When merged together, Sigma claims the resulting image quality is comparable to medium format files.

While I’ve never personally used the Sigma Quattro series, my interest as a portrait photographer is certainly piqued. If what Sigma claims is true regarding image quality being comparable to medium format, I may give it considerable thought. The current Sigma lens lineup is impressive and if the system offers tethered shooting through either Sigma’s Photo Pro software or a third party application, it may be quite the contender!

So far we do not have any official pricing or shipping information, but reports earlier this week suggested those could come on December 20th. If you’d like more information feel free to visit Sigma’s website here.